the Twilight books seem to be the trend of these weeks.
here two blog posts with notes on this phenomenon:
Jessica Papin on Vampires etc.
"God bless the vampires. They saved Christmas."
and this, from September 2008:
Overnight Success Takes 2 to 10 years
"For example, in the young adult world, Stephenie Meyer’s name is on everyone’s lips. As an author, her Twilight books seem to “come out of nowhere”. But the first book Twilight was originally sold in late 2003 and the initial hardcover of the title released in 2005."